CVE-2021-3580: 
NixOS vulnerability analysis and mitigation

A vulnerability (CVE-2021-3580) was discovered in nettle's RSA decryption functions that affects versions prior to 3.7.3. The flaw is related to how the functions handle specially crafted ciphertext. Since nettle is used with gnuTLS, there is a possibility that a remote client could crash a server compiled with gnuTLS when RSA is used for the initial key exchange (Redhat Bugzilla).

The vulnerability has been assigned a CVSS score of 7.5 (HIGH) with the vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. The issue lies in the RSA decryption functions of the nettle cryptographic library, which improperly handle specially crafted ciphertext inputs (NetApp Security).

When successfully exploited, this vulnerability could lead to application crash and denial of service (DoS). This is particularly concerning in systems where nettle is integrated with gnuTLS, as it could allow remote attackers to crash servers during the RSA key exchange process (Debian LTS).

The vulnerability has been fixed in nettle version 3.7.3 and later. Multiple vendors have released patches for their affected products. The fix was implemented through several commits in the nettle repository that address the RSA decryption function handling (Redhat Bugzilla).